I mean the problem is testing time, riot being scared to make actual changes, and following the same agent design lines
whenever they make a new agent they can only test how that character impacts the overall game so much, any amount of testing riot could do is suprassed by the playerbase the second it becomes playable, that testing also cant really account for future agnet or map additions and how those interactions will play out
riot is for some reason terrified of actually changing how abilities work so all they change is numbers, the only abilities that have actually been changed in the history of the game is yoru footsteps to clone and the harbor rework and both of those required a big fuss
they keep repackaging the same agent design and just delivering it in slightly different ways miks, clove, brim basically have the same smoke with slight durration tweaks, any new agents that come out dont really do new things anymore and even the new things are basically the same (waylay hinder versus stun is more or less the same), pretty sure every agent has 7+ cost ult now, all of the agents are becoming more and more homogenized even though at a surface level there is more options because the options just arent as different as they were at the start of the game